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How Do You Fix a Computer That Won’t Turn on But Has Power?

If your computer won’t turn on but shows signs of having power (like lights turning on or fans spinning), it indicates there might be a problem with the hardware or the connection between components. Here’s a step-by-step guide to troubleshoot and potentially fix the issue:

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A computer that shows signs of power but doesn’t boot up can be frustrating. This situation suggests that the power supply unit (PSU) is working, but something is preventing the system from completing its boot process.

Key Takeaways:

  • Check External Connections: Ensure all cables and peripherals are properly connected.
  • Inspect Internal Components: Loose or faulty components can prevent booting.
  • Power Cycle: A complete power drain can sometimes resolve the issue.
  • Check for Beep Codes: Listen for beep codes that can indicate specific hardware issues.
  • Minimal Boot: Attempt a boot with only essential hardware to rule out peripheral issues.
  • Consult Professionals: If you’re unable to resolve the issue, professional help may be necessary.

Troubleshooting Steps

Check External Connections

  • Power Cord: Ensure the power cord is securely connected to both the computer and the power outlet.
  • Monitor: Verify that the monitor is on, correctly connected to the computer, and set to the correct input.

Inspect Internal Components

  • Internal Cables: Check all internal cables to ensure they’re properly seated and not damaged.
  • RAM: Ensure RAM sticks are securely seated in their slots. Try reseating or testing with one stick at a time.
  • Graphics Card: If you have a dedicated graphics card, make sure it’s firmly seated in its slot. Consider reseating it as well.

Perform a Power Cycle

  1. Turn Off and Unplug: Turn off the computer and unplug it from the power source.
  2. Drain Remaining Power: Press and hold the power button for about 15-30 seconds to drain any residual power.
  3. Reconnect and Restart: Plug the computer back in and try turning it on.

Listen for Beep Codes or Check Diagnostic LEDs

  • Beep Codes: If your computer emits beep codes, note the pattern. These codes can indicate specific hardware issues.
  • Diagnostic LEDs: Some computers have diagnostic LEDs that can help identify which component is failing.

Attempt a Minimal Boot

  • Remove Non-Essential Hardware: Disconnect all non-essential hardware (external drives, extra RAM, peripherals) and try to boot with just the essentials (CPU, one stick of RAM, onboard graphics).

Check the Power Supply Unit (PSU)

  • PSU Test: If possible, test the PSU with a PSU tester or by using the paperclip test (only if you’re familiar with it and understand the risks).

Clear the CMOS

  • Reset BIOS/UEFI Settings: Clearing the CMOS can reset the BIOS/UEFI settings to their defaults, which can sometimes resolve boot issues. This can usually be done by shorting a specific jumper on the motherboard or removing and reinserting the CMOS battery.


A computer that won’t turn on despite showing signs of power can be affected by a range of issues, from simple connection problems to more serious hardware failures. By systematically checking connections, reseating components, and performing a power cycle, you might be able to identify and resolve the issue. However, if these steps don’t fix the problem, it may be time to consult with a professional technician.


Q: What should I do if reseating components doesn’t work?

A: If reseating doesn’t help, try testing with known good components or consult a professional.

Q: Can a faulty motherboard be the reason my computer won’t turn on?

A: Yes, a faulty motherboard can prevent the computer from booting, even if it shows signs of power.

Q: Should I attempt to fix the PSU myself?

A: Unless you’re experienced with electronics, it’s safer to have the PSU tested or replaced by a professional.

Q: How can I prevent these issues in the future?

A: Regular maintenance, ensuring proper ventilation, and using a surge protector can help prevent some hardware issues.

Q: Is it worth repairing an old computer that won’t turn on?

A: It depends on the computer’s age, its specs, and the cost of repair. Sometimes, investing in a new system might be more cost-effective.


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